5 Best L-Glutamine Supplements of 2025 [Full Comparison]

As someone who trains hard and pays close attention to recovery and gut health, Momentous L-Glutamine has become one of the few supplements I take consistently. I initially started using it to support muscle repair after intense workouts, but quickly noticed benefits beyond recovery, particularly with digestion and minimizing GI (gastrointestinal) distress. That alone makes it worth keeping in my daily routine.

One of the things I appreciate most is the peace of mind that comes from the NSF Certified for Sport certification, meaning it's been independently tested for purity, potency, and contaminants (a personal non-negotiable). It also dissolves easily, has no taste, and avoids the bloating or discomfort that some glutamine powders can bring.

That said, it’s not the cheapest option out there. You can definitely find less expensive glutamine supplements, but if you care deeply about ingredient sourcing and third-party testing, the slightly higher price is a good trade-off to make. If budget is your top concern, there are other options—but if quality, transparency, and effectiveness top your list, Momentous is a standout.

In short, if you’re looking to improve athletic performance or you’re someone recovering from high stress and/or wanting to improve your gut health, then this is a product well worth checking out.

Key Things to Know About This Product

• Third-Party Tested: Yes, GMP certified facilities 

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $15.99

• Number of Servings: 120

• Amount of L-glutamine per serving: 500 mg

• Serving Size: 1 capsule

• Subscription: No

• Free shipping: Yes (orders over $50)

Pros:

• Cost effective

• Good dose per serving

Cons:

• No NSF certifications

Now Foods L-Glutamine is popular with many people looking to improve intestinal health and immune health while keeping costs down. It’s highly cost-effective, delivering a solid 500 mg dose at $15.99 for 120 servings. For anyone on a budget—students, weekend warriors, or anyone stocking multiple supplements—this one keeps costs in check without skimping on quantity.

In terms of effects, customers report that it helps support athletic performance and maintain a healthy gut with no noticeable side effects. You don’t get the premium feel or reassurance of premium labels, but it still holds its own.

That said, the lack of NSF certifications might deter those who need guaranteed purity or compete at elite levels. If supplement testing and elite athlete safety are top priorities, you may want to look elsewhere. But for everyday fitness enthusiasts after a solid glutamine option at a fair price, Now Foods hits the mark.

Key Things to Know About This Product

• Third-Party Tested: Yes, NSF Certified for Sport 

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $63

• Number of Servings: 90

• Amount of L-glutamine per serving: 5 grams

• Serving Size: 1 scoop

• Subscription: Yes - subscribe and save 20%

• Free shipping: Yes - on all orders

Pros:

• NSF certified

• Free shipping

• Mixes easily

Cons:

• Price

Thorne L-Glutamine Powder is a premium supplement that customers return to again and again for both training, recovery, gut health and immune system support. Like Momentous, it holds the prestigious NSF Certified for Sport certification, which helps provide full confidence that it's been rigorously tested for purity, potency, and banned substances.

Each serving delivers 5 grams of L-glutamine, and it mixes easily into water or smoothies with no aftertaste or grit. It’s also gluten-free, vegan, GMO-free, and comes with free shipping—a nice bonus considering the higher price point.

At $63 for 90 servings ($0.70 per serving), it’s definitely more expensive compared to other options on the market like Momentous ($0.66 per serving).

Customers rate and review it highly for post-workout recovery and improved long-term gut health since incorporating it regularly into their routines.

If you value clean, third-party-tested supplements and don’t mind spending a bit more, Thorne L-Glutamine is a smart, reliable choice.

Key Things to Know About This Product

• Third-Party Tested: Yes, GMP compliant

• Money-Back Guarantee: Yes - 90-day money back guarantee

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $31.97

• Number of Servings: 60

• Amount of L-glutamine per serving: 1700 mg

• Serving Size: 2 capsules

• Subscription: Yes - subscribe and save 15%

• Free shipping: Yes - on all orders

Pros:

• Highly rated and reviewed by customers

• Physician formulated

Cons:

• Lower dosage than other options

• Not NSF certified

• 2 large capsules per serving — not ideal for those who dislike swallowing pills

AMMD L-Glutamine Capsules offer a clean, convenient option for anyone looking to support gut health, recovery, or immune function—especially if you prefer capsules over powders. Formulated by physician Amy Myers and GMP compliant, these capsules are third-party tested, vegan, gluten-free, and GMO-free, which checks a lot of boxes for quality and safety.

One of the biggest pros is the strong customer reviews—this product is clearly trusted by many. Customers also appreciate the 90-day money-back guarantee and free shipping, which make it easier to try without risk. At just over $30 for 60 servings, this product sits in the middle of the road when it comes to price—not a premium price tag, but not as competitive as others.

That said, there are a few trade-offs. The dosage is lower than many powders (1700 mg per 2-capsule serving), so it may not be ideal if you're looking for higher-intensity support. And if you dislike swallowing pills, the two large capsules per serving could be a drawback. It's also not NSF certified, so competitive athletes may want to look elsewhere for verified purity.

Overall, if you’re looking for a gentle, easy-to-use glutamine supplement with solid customer trust and clean ingredients, AMMD is a great place to start—especially for everyday gut health and immunity support.

Key Things to Know About This Product

• Third-Party Tested: Yes, Informed Choice

• Money-Back Guarantee: Yes

• Gluten Free: Yes

• GMO Free: Yes

• Vegan: Yes

Product Details:

• Price: $39.99

• Number of Servings: 30

• Amount of L-glutamine per serving: 5 grams

• Serving Size: 1 scoop

• Subscription: Yes - subscribe and save 10%

• Free shipping: Yes - on all orders over $99

Pros:

• Third-party certification from Informed Choice

• Unflavored and mixes easily

Cons:

• Price

• Not solely an L-glutamine supplement - also contains BCAAs, vitamin C, and electrolytes

Transparent Labs L-Glutamine BCAAs is a solid choice if you're looking for more than just a basic glutamine supplement. Each scoop delivers 5 grams of L-glutamine, plus a blend of BCAAs, vitamin C, and electrolytes—making it ideal for intra- or post-workout recovery. It's especially helpful on intense training days when you want to support both muscle repair and hydration in one hit.

The product is third-party tested by Informed Choice, which means it’s verified for quality and banned substances. It’s also vegan, gluten-free, and GMO-free, and mixes easily in water with no chalky texture. The unflavored version is a plus if you like to keep your stack simple or blend it with other supplements.

The downside? At $39.99 for 30 servings ($1.33 per serving), it’s an expensive form of L-glutamine. Plus if you're looking strictly for L-glutamine, this may be more than you need. Still, if you appreciate the all-in-one recovery formula, it offers good value.

Transparent Labs L-Glutamine BCAAs is a great pick for active individuals who want performance support that goes beyond just glutamine—without compromising on quality.